Summary of Patient Eligibility Criteria Histological confirmation of glioma, grades II - IV; prior first-line treatment with surgery, radiotherapy and chemotherapy for malignant (grades III and IV) gliomas; age > 18 years; life expectancy >8 weeks; Karnofsky Performance Status ≥ 60; adequate organ function; signed patient informed consent; willingness to forego additional therapy until evidence of disease progression.